Arc splitter plate design for oil circuit breaker



1966 L. D. MOCONNELL, 3,267,242

ARC SPLITTER PLATE DESIGN FOR OIL CIRCUIT BREAKER File d March 9, 1964 Ia 5- 3 INVENTOR. y 5/ Zak/v! .0 M caw/la! 52 zr/eazamq fiwee fiseaJFFg/r United States Patent 3,267,242 ARC SPLITTER PLATE DESIGN FOR OILCIRCUIT BREAKER Lorne D. McConnell, Sierra Madre, Califi, asslgnor toI-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation ofPennsylvania Filed Mar. 9, 1964, Ser. No. 350,268 6 Claims. (Cl.200-450) This invention relates to oil circuit breakers, and morespecifically relates to a novel interrupter structure for an oil circuitbreaker which provides improved discharge of oil and arcing productsthrough the ports of the interrupter chamber.

Interrupter structures for oil circuit breakers are well known to theart, and may be seen, for example, in detail in copending applicationSerial No. 2,390, now United States Patent No. 3,128,360, filed January14, 1960, in the name of Earl B. Rietz, entitled Single ContactInterrupter, and assigned to the assignee of the present invention.

Such interrupter structures generally comprise are splitter platesarranged within the interrupter chamber which force the venting of areproducts from a plurality of separate ports in the interrupter chamberhousing. A great variety of splitter forms and reservoir shapes havebeen employed. The form and shape of the reservoir and the positioningof the are within or through such a chamber area has, in many previousinterrupter chambers, allowed for the development of a circular flowpattern of arc products and oil. Such flow may result in the entrapmentof ionized are products within the interrupting chamber in reservoirchambers.

The principle of the present invention is to form an arc splitter platein such a manner that oil and contaminated products are necessarilyforced away from the rear of the small chambers and out of the ventingports due to the pressure which exists during arcing conditions. Thus,the rear of the chamber is provided with a projecting section whichinhibits a circular flow pattern and necessarily turns back oil throughthe arc column to exhaust the oil at the venting ports. This flowpattern efiectively breaks up and cools the ionized gas column effectinginterruption at current zero.

Moreover, the novel construction of the splitter plates of the presentinvention provides a region in front of the movable contact whichpermits communication between the adjacent oil reservoirs whereby anaxial blast may be applied to the are along with a radial blast throughthe venting ports, and also permits room for the formation of an axiallydirected arc. Moreover, the openings in the splitter plates closelyconfine the arc to a linear column, this column being held central tothe axis of the exhaust passage and closely disopsed to the inner throatof this passage.

Accordingly, a primary object of this invention is to provide a novelconstruction for the splitter plates of an oil circuit breaker whichpermits more complete exhaust of the are products from the interrupterchamber.

Another object of this invention is to improve the ventingcharacteristics of the interrupter structure of an oil circuit breaker.

A further object of this invention is to provide a novel arrangement foran oil circuit breaker which is simple and relatively inexpensive inconstruction.

These and other objects of the invention will become apparent from thefollowing description when taken in connection with the drawing, inwhich:

FIGURE 1 is a cross-sectional view taken through an interrupterstructure constructed in accordance with the present invention.

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FIGURE 2 is a top view of one of the arc splitter plates of FIGURE 1.

FIGURE 3 is a cross-sectional View of FIGURE 2 taken across the line 33in FIGURE 2.

FIGURE 4 is a top plan view of the lowermost splitter plate of FIGURE 1.

FIGURE 5 is a cross-sectional view of FIGURE 4 taken across the line 55in FIGURE 4.

FIGURE 6 is a top view of the upper plate of the interrupter of FIGURE1.

Referring now to the figures, and particularly to FIG- URE 1, I haveshown therein an interrupter structure which could, for example, be usedas illustrated in above noted'copending application Serial No. 2,390,now United States Patent No. 3,128,360, which is incorporated herein asa part of the present invention.

More specifically, the interrupter structure of FIG- URE 1 is comprisedof a container 10 which can be formed of any suitable material and has apredetermined number of venting ports such as venting ports 11, 12 and13 in the walls thereof. Container 10 then has a constricted portion 14which serves to receive a throat bushing 15, as illustrated. Thecontainer 10 additionally has an interior key member 16 which serves tokey the various plates to be contained by container 10, as will bedescribed more fully hereinafter.

The upper portion of container 10 is then provided with suitable studs20 and 21 for connecting the compression ring 22 to a suitable adaptionmeans or bushing which is to carry the interrupter of FIGURE 1 within anoil filled tank of a circuit breaker.

A contact block which has contact fingers 23 and extending arcingcontact finger 24 extending therefrom is then suitably fixed in positionwith respect to ring 22 where these contact fingers are arrangedcircularly about the hub 25 in the usual manner, and as it shown in thecopending application Serial No. 2,390, now United States Patent No.3,128,360, noted above. As is also standard, a bayonet-type contactschematically shown by the dotted line 26 can move upwardly and intoengagement with contacts 23 and 24 and is movable out of engagementtherewith and from the bottom of throat bushing 15 when contact 26 ismoved to its disengaged position.

The interior of container 10 then includes the various plates 30, 31, 32and 33 which are supported at the bottom by throat bushing 15 and arecompressed at the top by the compression ring 34 of insulation materialwhich has a clamping ring 35 threadably received by threads 36 on theinterior of chamber 10 and threaded downwardly to compress the stack ofplates.

The upper plate 33 is illustrated in FIGURE 6 where it is shown that theplate has a circular opening 40 therein which has an extending portion41 for receiving the extending arcing contact finger 24. Plate 33 alsohas a notch 42 therein which is keyed into keying member 16 to insureappropriate angular alignment of plate 33.

Each of plates 31 and 32 are then constructed in the manner shown inFIGURES 2 and 3 for plate 32. The plate 32, as well as the other variousplates of FIGURE 1, may be formed of a suitable vulcanized fibre sheet,or any other suitable material, and has a keying notch 50 therein whichcooperates with key 16 to insure proper alignment within chamber 10.

In accordance with the invention, the rear of the plate 32 is providedwith an extending tip portion 51 which provides two flow chambers 52 and53 atop the lower platform surface 54. Each of chambers 52 and 53 thenjoin adjacent port 11 for the case of plate 32, and port 12 for the caseof plate 31, as shown in FIGURE 1.

An opening 55 which is elongated at the port region 56 is then providedin the lower platform 54 to provide for passage of the movable contact26 of FIGURE 1 with room being left at region 56 for the passage of anarc and arcing products during interrupting conditions.

The lowermost plate 30 (FIGURES 2, 4 and 5) which has the keying notch60 therein for reception "by key 16 of FIGURE 1 is formed in an almostidentical manner to that of plate 32 where similar numerals have beengiven to elements of the plate. Thus, plate 30 has the two separatechambers 52 and 53 which are isolated by projection 51 and join in achannel 61 which is adjacent the lower port 13. The opening throughplate 30 is a circular opening 62 which is sufficiently large to receivecontact 26. It will be noted that the channel 61 of plate 30 is somewhatsmaller than the outlet channel of plates 31 and 32. Moreover, there isa relatively close fit between the contacts 26 and opening 62 of plate30. During interrupting conditions, this will insure sufficient pressureto cause venting operation at leastin vents 11, 12 and 13 to be built upwithin chamber until the contact rod 26 leaves :the throat bushing 15.

During arcing conditions, and in accordance with the invention, there issubstantial pressure of oil and are products which exist in the chambers52 and 53 defined by each of plates 30, 31 and 32. The projection 51 ispositioned to inhibit the development of a circular flow pattern.However, forces on the are or random motion of the arc column within thechamber might be such as to initiate a circular flow within the chamber.The positioning and shape of the projection 51 will result in a flowpattern, shown by arrows 70 and 71 in FIGURE 2, that will force oil fromthe rear of the reservoir to be projected forward toward the exhaustopenings 11, 12 and 13 and across the arc column within the confines ofthe openings through plates 55. This flow pattern effectively breaks upand cools the ionized gas column effecting interruption at a currentzero.

Although this invention has been described with respect to preferredembodiments thereof, it should be understood that many variations andmodifications will now be obvious to those skilled in the art, and it ispreferred therefore that the scope of the invention be limited not bythe specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:

1. An arc splitter plate for the interrupter structure of an oil circuitbreaker; said plate having a platform section and a rim sectionextending from said platform section; said platform section having acontact receiving opening therethrough; said rim section having anoutlet opening therein, and a single inwardly projecting rib section onthe side of said platform directly opposite said outlet opening; saidrib defining two paths 'of flow for oil atop said platform from the saidrib toward said opening and bounded by the inner walls of said rim.

2. The splitter plate of claim 1 wherein said contactreceiving openinghas a generally circular shape with an elongated section extendingtoward said outlet opening.

3. An interrupter structure for an oil circuit breaker; said interrupterstructure including a tubular interrupter housing having axiallydisplaced ports therein, and a stack of a plurality of parallel arcsplitter plates contained within said tubular housing and extendingperpendicularly to said housing; each of said are splitter plates havinga platform section and a rim section exending from said platformsection; said platform section having a contact receiving opening'therethrough; said rim section having an outlet opening therein, and asingle inwardly projecting rib section on the side of said platformdirectly opposite said outlet opening; said ri'b defining two paths offio-w for oil atop said platform from the said rib toward said openingand bounded by the inner walls of said rim; said outlet opening of eachof said arc splitter plates being adjacent a respective port of saidplurality of ports.

4. The interrupter structure of claim 3 wherein the last of said stackof arc splitter plates has a smaller outlet opening than the outletopenings of the other of said are splitter plates.

5. The interrupter structure of claim 3 wherein the last of said stackof arc splitter plates has a circular contact receiving opening in itssaid platform and the remaining plates of said are splitter plates havegenerally circular contact receiving openings with elongated sectionsextending toward their said outlet openings; each of said openings beingaxially aligned with one another.

'6. The interrupter structure of claim 5 wherein the last of said stackof arc splitter plates has a smaller outlet opening than the outletopenings of the other of said are splitter plates.

References Cited by the Examiner UNITED STATES PATENTS 1,955,216 4/1934Whitney et al. 200 3,128,360 4/1964 Rietz 200-150 FOREIGN PATENTS870,998 6/ 1961 Great Britain. 927,548 5/ 1963 Great Britain.

ROBERT K. SCHAEFER, Primary Examiner.

ROBERT S. MACON, Examiner.

1. AN ARC SPLITTER PLATE FOR THE INTERRUPTER STRUCTURE OF AN OIL CIRCUITBREAKER; SAID PLATE HAVING A PLATFORM SECTION AND A RIM SECTIONEXTENDING FROM SAID PLATFORM SECTION; SAID PLATFORM SECTION HAVING ACONTACT RECEIVING OPENING THERETHROUGH; SAID RIM SECTION HAVING ANOUTLET OPENING THEREIN, AND A SINGLE INWARDLY PROJECTING RIB SECTION ONTHE SIDE OF SAID PLATFORM DIRECTLY OPPOSITE SAID OUTLET OPENING; SAIDRIB DEFINING TWO PATHS OF FLOW FOR OIL ATOP SAID PLATFORM FROM THE SAIDRIB TOWARD SAID OPENING AND BOUNDED BY THE INNER WALLS OF SAID RIM.